Device and method for handling workpieces in particular vehicle chassis

ABSTRACT

A device ( 10 ) is provided for handling workpieces, in particular vehicle chassis ( 22 ) of modular construction, and having a first module with a handling line ( 12 ) in turn having one or several handling regions ( 14 ) for surface handling of the workpieces ( 22 ), and a guide device ( 44 ) along the handling line ( 12 ). A second module has one or several carriages ( 20   b ) to which the workpieces ( 22 ) may be fixed and moved along the guide device ( 44 ). Various types of second module may be combined with the first module to achieve various configurations of the whole device ( 10 ) with regard to throughput and flexibility.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device and method for handling workpieces, inparticular vehicle chassis.

Such a system comprises a handling line having a plurality of successivehandling regions in which the workpieces are introduced for surfacetreatment.

A handling region may, for example, be an immersion tank containing atreatment fluid, but the term handling region may be defined as any kindof booth or tank whenever a workpiece undergoes treatment therein. Suchtreatment may include, for example, a washing operation. Other examplesinclude immersion phosphating, pre-treatment for immersion coating,powder coating, wet-paint coating and the like.

2. Prior Art

Previously known devices for the surface treatment of workpieces such asvehicle chassis in immersion baths or treatment booths are divided intocontinuously conveying devices and discontinuously conveying devices.

In the case of continuously conveying systems, the chassis are fastenedinside suspension gear and a chain drive is used to convey them alongthe handling line, lower them into the immersion baths, convey themthrough the immersion baths and lift them out of the immersion bathsagain. A continuously conveying system for the surface treatment ofvehicle chassis is described in DE 196 41 048 A1. In this device, thevehicle chassis are each held by rotary frames that are moved a fixeddistance apart from one another at a uniform speed with the aid of acommon conveying means above a plurality of treatment tanks. The vehiclechassis are introduced into and removed from the immersion baths bymeans of a selective rotational movement that can be coupled rigidly,via guide rails, to the translatory movement of the rotary frames. Therotary frames are guided by a revolving chain system and are thereforeguided rigidly in relation to one another and at a continuous speed,both in the region of the handling line above the immersion baths andduring return travel.

Discontinuously conveying systems are known in the prior art, too andare referred to as cyclical systems. In the case of cyclical systems,the vehicle chassis are moved on article mounts over the immersionbaths, stopped there and dipped into the treatment bath with the aid oflifting means, such as hoists or swivel gear, and, after the processtime has elapsed, the chassis are lifted or swivelled out of the bathagain.

An example of such a system is described in DE 43 04 145 C1 or DE-U-20022 634.7.

Choosing between a continuously conveying device and a discontinuouslyconveying device must take account of the specific pros and cons of bothbasic ideas. For instance, the continuously conveying devices are morereliable because their operation requires fewer drive motors, whereasthe individually timed article mounts of cyclical systems are morelikely to malfunction as a result of the plurality of individuallycontrolled motors. The maximum throughput of workpieces per time unit inthe case of continuous devices is, furthermore, higher than that ofcyclical systems. The advantage of cyclical systems, on the other hand,is the high degree of flexibility regarding workpiece handling as aresult of the ability to individually drive the individual articlemounts.

In the automotive sector, efforts are being made to operate the systemswith high throughputs. At the same time, however, a high degree ofprocess flexibility is desired as well, because once a system has beenset up in an automotive plant, it may be intended to perform differentworkpiece-handling operations in the future.

SUMMARY OF THE INVENTION

The invention is based on the object of designing a device and methodfor handling workpieces, in particular vehicle chassis, which combinesthe advantages of a high throughput with the advantage of a high degreeof flexibility.

This problem is solved by a device comprising the features of modularconstruction for handling workpieces (22), in particular vehicle chassis(22), having a first module, in turn, having a handling line (12) withone or more handling regions (14) for the surface treatment ofworkpieces (22) and a guide device (44) along the handling line (12) anda second module having one or more carriages (20; 40; 60) to which theworkpieces (22) may be fixed and which may move along the guide device(44), wherein various tynes of second modules may each be combined withthe first module and method comprising the features of initiallytransporting a workpiece by first conveying means to a first transferstation, pivoting a carriage up around a pivoting shaft until thecarriage holds the workpiece, nassing through the handling line as faras a second transfer station while performing an additional, sectionalrotational movement for introducing the workpiece into, or removing itfrom, one or more handling regions, pivoting the carriage down aroundthe pivoting shaft in the region of the second transfer station, and atthe same time removing the workpiece by a second conveying means, andtransporting the carriages that have been pivoted through approximately90 degrees out of the horizontal plane back to the first transferstation. Advantageous embodiments of the device and method according tothe invention are described.

The invention is based on the idea of designing a device of modularconstruction for handling workpieces, in particular vehicle chassis. Afirst module comprises a handling line having one or several handlingregions, such as immersion baths, for the surface treatment ofworkpieces, and further comprises a guide device along the handlingline. A second module comprises a plurality of carriages to which theworkpieces may be fixed and which may be moved along the guide device,i.e. along the handling line.

The essence of the invention lies in that various types of second modulemay each be combined with the first module. In this way, carriages thatthemselves do not have any drive motors and which are forcibly guidedthrough the device essentially by way of the aforementioned continuousmeans can be used in the device. Yet carriages that have their owntravel drive as well as separate rotary drives for moving the workpiecesinto the immersion baths, moving them within the immersion baths andremoving them from the immersion baths can also be used in the device.Combined with the unvarying first module, these carriages ensure thefeatures of cyclical systems. Apart from the two aforementionedcarriages resembling holding frames in the case of continuouslyconveying systems and the article mounts of cyclical systems, it is,however, possible to conceive of intermediate solutions, which will bedescribed below as hybrid solutions. Thus, it is, for example, feasibleto use carriages in the device according to the invention that do nothave their own travel drive and which are therefore forcibly guidedalong the handling line, whereas the carriages have a separate rotarydrive and consequently it is possible to individually control therotational movement, even to the extent of “skipping” individualhandling regions. Conversely, the device according to the invention may,furthermore, be equipped with carriages that each have their own traveldrive, but in which the rotational movement is forcibly coupled to thetranslatory movement of the carriages, as is the case in theabove-described continuously conveying system according to DE 196 41 048A1. Such hybrid solutions therefore lie midway between theabove-described basic ideas of a continuously conveying device and of acyclical system.

As far as operators of the device according to the invention areconcerned, it is therefore possible to refit, with little outlay, theentire system in that they can switch between a continuously conveyingsystem, a cyclical system and the aforementioned hybrid solution. Thus,for example, the system can be operated on a continuously conveyingbasis when the device is used to coat vehicle chassis, as long as theaim is maximum throughput for mass production, whereas if the productionquantity is reduced or if the corresponding model is being phased out,the device can be converted into a cyclical system in that merely adifferent second module is combined with the first, unvarying basicmodule.

A further advantage of the device according to the invention is that aspart of small batch production, manufacturing costs can be reduced as aresult of largely using common components between varyingly configureddevices.

To accomplish a flexible solution as described above, the carriagescannot be guided on a revolving chain throughout the entire system,because this would contradict the basic idea underlying a cyclicalsystem and a hybrid system with its own travel drive. For this reason,the carriages must be guided such that only if required will they beguided in relative to one another, so to speak, as a rigid unit withinthe region of the handling line. The method according to the inventionfor handling workpieces, in particular vehicle chassis, is thereforecharacterized in that the workpieces are transported, initially by afirst conveying means, to a first transfer station in which theworkpieces are joined to the carriages. For this purpose, a carriage isswung up around a pivoting shaft until the carriage holds the workpiece.The workpiece held on the carriage then passes through the handling lineas far as a second transfer station at the end of the handling line,with an additional, sectionally rotational movement taking place inorder to introduce the workpiece into or remove it from one or morehandling regions. After the workpiece has reached the second transferstation, the carriage swings down around the pivoting shaft and at thesame time the workpiece is carried away by a second conveying means. Thecarriages pivoted through approx. 90° out of the horizontal plane aretransported back to the first transfer station.

According to a preferred embodiment, the guide device is disposed merelyon one side of the handling line. That member of the device which is tobe made available for potential maintenance is covered by this measure,and space is saved, too. If the entire device is configured to include acontinuously conveying system, the rotary shafts can, furthermore, beshorter in design in order to effect rotation of the workpieces, sincethese have to be disposed only on one side of the carriages.

The guide device preferably comprises at least one rail. Thisconstitutes the simplest design for a guide device.

In this embodiment, the carriages preferably have rollers that roll onthe at least one rail of the guide device and which at the same timeaccurately define the position of the carriages relative to the rails.

According to a preferred embodiment of the invention, the first moduleadditionally comprises a return means, preferably in the form of aconveyor belt or chain conveyor, for conveying the carriages from thesecond transfer station to the first transfer station. The use of aconveyor belt represents a simple idea based on mounting the carriagesin a friction-fit manner. Conveyor belts or chain conveyors permit thecarriages to be returned in any position and at a speed that isindependent of the average speed of the carriages in the region of thehandling line. By providing an independent return member, theflexibility of the entire device can be further increased, and thereturn means can be used as a carriage buffer.

If the return means is adapted such that the carriages are conveyed fromthe second transfer station to the first transfer station in a shortertime than it takes the carriages to be conveyed from the first transferstation to the second transfer station, a complete system will requirefewer carriages. In the case of carriages that have their own traveldrive, no conveying means is needed in the region of return travel,because these carriages move independently. While maintaining a uniformthroughput of workpieces to be handled, rapid return entails the use offewer carriages in the device, since the dwell time in the region ofreturn travel is shorter.

As already described above in conjunction with the method according tothe invention, the device is preferably designed such that the carriagesin the second transfer station are pivoted through an angle of approx.90° around a pivoting shaft in the region of the guide device, and thatthe carriages in the first transfer station are pivoted back through thesame angle in the opposite pivoting direction. This solution has theadvantage that during return travel, the carriages take up just a smallamount of space within the overall device. This is due to the fact thatthe carriages can be returned upright next to the treatment baths.

Depending on the system configuration, however, the carriages can alsobe returned upright above the handling line. This is desirable wheneverthe workpieces to be handled and being transported from the firstconveyor means to the first transfer station are to be gripped by thecarriages from above. In this case, it is advisable to upwardly pivotthe carriages in the region of the second transfer station from theworkpieces to be handled and correspondingly to downwardly move theregion of the first transfer station back close to the workpieces to behandled. In accordance with the preferred embodiment of the invention,however, the movement is effected in precisely the opposite direction.In the region of the second transfer station, the carriage are, so tospeak, tilted away underneath the workpieces, are pivoted throughapprox. 90° around the pivoting shaft in the region of the guide device,are conveyed at an increased speed back to the first transfer station,where they are pivoted from below back close to the workpieces to behandled until these are held by the pivoting means.

The pivoting shaft is preferably disposed essentially parallel to theguide device and on that side of the guide device and of the carriageswhich faces away from the one or more handling regions. The suitablelocation of the pivoting shaft enables the carriages to be pivoted intothe return position in such a way that during return travel, they do notcollide with the guide device or carriages on the handling line.

The carriages and guide device are preferably designed such that whenthe workpieces are being handled, all the bearings and joints are eachdisposed outside the one or more handling regions. If there is aplurality of immersion baths of the type mentioned at the start, eitherit will be necessary to take special sealing measures to prevent thetreatment fluids from penetrating the bearings, or the service life ofthe bearings and joints will be reduced accordingly. Particularpreference is therefore given to a suitable arrangement of the bearingsand joints outside the handling regions.

The carriages preferably comprise an outer frame and an inner frame thatrevolves around a rotary shaft relative to the outer frame, with theworkpieces being attachable to the inner frame. This design enables thecarriages to move with the outer frame along the guide device in theregion of the handling line, while the complex rotational movementsadapted to the respective handling region are performed only by theinner frame with the workpiece attached thereto. In particular, thisdesign has the advantage that if carriages which create a continuouslyconveying system are used, the individual carriages can be coupledtogether easily, since the outer frames do not undergo the complexrotational movements of the workpieces.

According to a preferred embodiment, the rotary axis is disposed in anessentially horizontal and perpendicular manner relative to thedirection of the carriages' movement along the handling line.

A continuously conveying system can be obtained by choosingspecial-purpose carriages that can be coupled together in the region ofthe first transfer station and which can be separated from one anotherin the region of the second transfer station. Consequently, in theregion of the handling line, the carriages can each be conveyed at aspecified distance in relation to one another, and, like a train, thecarriages can be pulled or pushed through the handling line. At the sametime, however, the aforementioned rapid return of the carriages from thesecond to the first transfer station is made possible by the separationof the carriages from one another in the region of the second transferstation, and the number of carriages to be used in total can, moreover,be reduced in the case of a continuously conveying system.

In this embodiment of the invention, it has proved particularlyadvantageous to equip the outer frames of the carriages with frontcoupling members and rear coupling members that are designed so that therear coupling member of each carriage can form a detachable form-lockedconnection with the front coupling member of the following carriage.This design makes it unnecessary to adjust chains, and while thecarriages are being pivoted in the region of the first transfer stationand second transfer station, the carriages are easy to connect togetherand separate from one another again in that a form-locked connectionwhich acts only on the horizontal plane is formed, and in that when thecarriages pivot downwards or upwards through 90°, the coupling memberscan engage with the complementarily shaped coupling members of anadjacent carriage.

According to a preferred embodiment, the carriages, furthermore, have aconnecting means, preferably a hook-shaped projection, disposed in theregion of the outer frame, with which projection a pulling means caninteract. Such a pulling means or drive means is advantageously disposedin the region of the second transfer station and is designed such as toform a detachable connection with the connecting means of that carriagewhich is nearest to the second transfer station in the region of thehandling line, whereby this carriage can be forcibly conveyed, by thepulling means, to the second transfer station. That carriage which isnearest to the second transfer station in the region of the handlingzone is therefore coupled in a manner similar to a train and is forciblyconveyed, with the aid of the pulling means, to the second transferstation, from where the workpiece is accepted by the second conveyingmeans and transported away, and the carriage is simultaneously detachedfrom the workpiece. The detachment of the carriage from the workpiecesimultaneously disengages the connection both with the pulling means andthe coupling connection with the following carriages in the region ofthe handling line. Consequently, the pulling means must then once againestablish a connection with that carriage which is nearest to the secondtransfer station in the region of the handling line. This solution isvery simple and permits continuous conveyance by way of the describedpulling technique. Alternatively, however, it is possible to use apushing means which is disposed in the region of the first transferstation and pushes the carriages connected together toward the secondtransfer station.

The second module, furthermore, preferably comprises a control means inthe region of the guide device which interacts with the carriages suchas to control a relative rotational movement between the outer frame andinner frame around the rotary shaft. This embodiment relates to acontinuously conveying version or to one of the two possible hybridversions in which the carriages do not have their own rotary drive. Thetranslatory movement of the carriages, with the aid of the guide device,therefore controls the relative rotational movement between the outerframe and inner frame and guides the immersion of the workpieces intothe treatment baths.

The control means according to this embodiment comprises preferably aguide rail with inclined guide portions, which rail interacts with alever assembly connected in a torsionally rigid manner to the innerframe. This type of control means is simple to put into effect and islargely maintenance-free, while it is possible to produce a controlledrotational movement that is under control at any time.

As part of the modular construction according to the invention, thecarriages may have a rotary drive on each carriage, which drive isconnected to the carriages' inner frame in a torsionally rigid manner atthe output side.

Additionally, the carriages may have both a travel drive for thetranslatory movement of the carriages along the handling line and arotary drive for the rotational movement of the inner frame relative tothe outer frame, with the translatory movement being independent of therotational movement. When they form part of the second module, suchcarriages turn the overall device into a cyclical system.

Finally, the carriages may have a means for lifting or lowering therotary shaft in order to rotate the inner frame relative to the outerframe. This can be effected in any manner known to the person skilled inthe art, for example by means of a knuckle-joint guidance mechanism.Furthermore, it is possible to pivot the rotary shaft in that as analternative to or in addition to lifting or lowering this shaft, it ispositioned at an angle.

If carriages that have their own travel drive and/or rotary drive areused, information and/or power is transferred from the first module tothe carriages in a preferably contactless manner, particularlyinductively. This solution is less prone to malfunctioning than thealternative solution that uses sliding contacts.

A BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of examples based on theattached figures, in which

FIG. 1 is an overall view of a device according to the invention in theregion of the second transfer station;

FIG. 2 is a sectional view of the device in the region of a treatmentbath, the section being disposed perpendicular to the translationaldirection;

FIG. 3 shows an embodiment for a carriage without its own drive;

FIG. 4 shows a carriage with its own rotary drive, though without itsown travel drive;

FIG. 5 shows a carriage that has both its own rotary drive and its owntravel drive;

FIG. 6 shows schematically a portion of the device according to theinvention in the region of the second transfer station having carriagescorresponding to the embodiment according to FIG. 3;

FIG. 7 shows schematically the movement of the vehicle chassis in whicha carriage according to FIG. 3 is used;

FIG. 8 is a view similar to FIG. 7 and shows schematically a deviceaccording to the invention having carriages according to the embodimentin FIG. 3 in the region of the treatment baths and the second transferstation;

FIG. 9 shows, in a section perpendicular to the direction of translatorymovement, the pivoting of the carriages in the region of the first andsecond transfer stations;

FIG. 10 shows a cross-section of the tunnel of the overall system in theregion of a handling station, wherein once again carriages according tothe embodiment in FIG. 3 are used;

FIG. 11 shows schematically the coupling means for coupling together theindividual carriages according to FIG. 3;

FIG. 12 shows a further embodiment of the invention having carriagesaccording to FIG. 5, which carriages have both their own travel driveand their own rotary drive;

FIG. 13 shows a top view of such a travel drive having its own driveunits, and

FIG. 14 shows in detail the arrangement of the travel drives in theembodiment according to FIG. 12 within the system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following embodiments of the invention each use identical referencenumbers to refer to identical parts.

FIG. 1 shows a schematic view of a device according to the invention,which device is used to coat automotive chassis. The basic principles ofthe device are, however, equally applicable to other systems havingdifferent handling stations for the handling of workpieces. The overallsystem 10, of which only the part at the output side is depicted in FIG.1, comprises a tunnel 12 and a plurality of tanks 14 which contain atreatment fluid and into which the workpieces to be handled are to beimmersed. In addition to guides 16, FIG. 1 depicts a second transferstation 18 in which the workpieces, which are held by their owncarriages (not shown) and have passed through the system according toFIG. 1 in the plane of projection from left to right, are delivered to adownstream conveying means.

The system's main components shown in FIG. 1, such as the tunnel, tanksand a guidance mechanism with transfer station, are parts of the modularsystem that are common to all the various configurations of the overallsystem discussed below and are designated as a first module. Inconsequence, these parts are, so to speak, the basic components of themodular system described in more detail below.

FIG. 2 shows schematically a section perpendicular to the direction ofthe translatory movement through the system and, likewise schematicallyindicated, tunnel 12, a treatment tank 14 and the first transfer station18. The depiction according to FIG. 2 is intended to represent only byway of clarification the immersion of a vehicle chassis 22 into the tank14, while at the same time the second transfer station 18 is depicted tocorrespond to an offset section that shows, on the one hand, thetransfer station 18, but on the other hand passes through a tank 14. Theregion of the transfer station depicts a carriage 20 a that correspondsto the subsequently explained embodiment according to FIG. 3 without itsown drive means and is downwardly pivoted into a return position. At thesame time, FIG. 2 also shows the carriage 20 b that holds the vehiclechassis 22 in the region of the handling line. As will be explainedlater on the basis of more accurate diagrams, the carriage in the regionof the transfer station is downwardly tilted through 90° around apivoting shaft from the position corresponding to the carriage 20 b intothe position corresponding to the carriage 20 a, whereby at the sametime the handled vehicle chassis is released and can be transported awayvia a conveying means. The carriage assembly is located below a grating24 accessible to personnel, as will be subsequently evident with evengreater precision from FIG. 14.

As part of the system's modular construction according to the invention,the first module depicted in FIG. 1 can be combined with a second modulethat comprises variously designed carriages.

FIG. 3 depicts a carriage 20, as already schematically indicated in FIG.2. The carriage 20 has an outer frame 26 and an inner frame 28 that isdesigned to hold the vehicle chassis to be handled. The designations“outer frame” and “inner frame” here are not intended to be interpretedto the extent that the inner frame is located within the enclosing outerframe. Rather, with reference to the system shown in FIG. 1, thisdesignation was chosen to the extent that the outer frame moves outsidethe region of the handling devices, whereas the inner frame holds, inthe region of the treatment tanks, those vehicle chassis that are to behandled. The outer frame 26 is provided with rollers 30 that roll on aguide device and hold the outer frame along the guide device, each in adefined position relative to the guide device.

The inner frame 28 is designed to revolve relative to the outer frame26, with the inner frame being moveable around the rotary shaft 32relative to the outer frame. The inner frame 28, furthermore, hasholding projections 34 that are depicted only schematically in FIG. 3and which serve to hold the workpieces to be processed, in thisparticular exemplary embodiment vehicle chassis. Moreover, the outerframe 26 is provided with coupling projections (50 a, 50 b). Finally,the outer frame has a connecting means (not shown) that serves to couplea pulling means or drive means for pulling a plurality of outer framesthat are connected together, similar to a train that has several railwaycarriages.

The carriage without its own travel drive or rotary drive according toFIG. 3 has a lever assembly 38 having a plurality of lever arms androllers 40 disposed at the ends of the lever arms, which interact with aguide rail that has inclined guide portions in order to cause acontrolled rotation of the inner frame 28 that is under control at anytime relative to the outer frame 26. For this purpose, the rollers 40roll on the levers of the lever assembly 38 within the guide rail 48depicted in FIG. 9. In the case of the upwardly and downwardly inclinedportions of the guide rail, the inner frame 28 is pivoted around therotary shaft 32 relative to the outer frame 26. The shape of the guideportions of the guide rail or control guidance rail therefore achievesdesired complete and partial rotations in just one or alternatingdirections of rotation respectively.

The second module of the overall system, which system can be combinedwith the basic system as a system module, is formed by the guide rail 48together with the carriage 20 depicted in FIG. 3 and the coupling means50 a, 50 b between individual carriages and a pulling means in theregion of the second transfer station for pulling the outer frames thathave been connected together. If a carriage according to FIG. 3 is used,the overall system can be designed as a continuously conveying system.

The embodiment according to FIG. 4 uses a carriage 40 which differs fromthe carriage 20 only in terms of a single component. The difference isthat instead of the lever assembly 38, the rotation around the rotaryshaft 32 is effected by a rotary drive 42. The other members correspondto those in FIG. 3, with the result that reference can be made to theabove explanations. The carriage according to FIG. 4 is used in theoverall system 10 essentially with the same components of the secondmodule as described above in conjunction with the carriage 20.Nevertheless, the carriage 40 according to FIG. 4 does not require aguide rail with inclined guide portions that interacted with the leverassembly in the embodiment according to FIG. 3.

FIG. 5 shows a third alternative embodiment of a carriage in which theinner frame 28 once more corresponds to the inner frame according to theembodiments in FIGS. 2 and 4. The outer frame, however, has much smallerdimensions than in the embodiments according to FIGS. 3 and 4 and inturn has travel rollers 30 for interacting with the guide device (notshown). The essential difference between the carriage 60 according toFIG. 5 and the carriage 40 according to FIG. 4 is that not only therotary drive 42, but also an additional travel drive 62 are provided,which, like the rotary drive 42, is controlled via an accompanyingcontrol means 64.

If a carriage 60 according to FIG. 5 is used, it is necessary to provideneither guide rails for controlling the rotational movement nor couplingmeans between the outer frames 26, nor connecting means or a returnconveyor nor a guide device for pulling a series of carriages coupledtogether, because the carriages are independent of the translatorymovement both in relation to the rotational movements to be executed andare independent in relation to the translatory movements of the othercarriages. Provided the various carriages successively passing throughthe handling region therefore do not collide with one another, anytranslatory movements and rotational movements are possible in the caseof the carriage 60 according to FIG. 5, whereas in the case of thecarriage 40 according to FIG. 4, the translatory movement of theindividual carriages is coupled together and only the rotationalmovement can be executed independently thereof. Finally, in the case ofthe carriage 20 according to FIG. 3, the translatory movements of thecarriages that successively pass through the handling line are rigidlycoupled together and, moreover, the rotational movement of each carriageis coupled to the translatory movement.

FIG. 6 shows schematically the second transfer station 18 when carriages20 according to FIG. 3 are used. The vehicle chassis 22 conveyed in theplane of projection from right to left are held on the holding means ofthe inner frames 28, and the outer frames 26 run, with the rollers 30,along guide rails 44, while the lever assembly 38 controls therotational movement of the inner frames. Thus at the upper right-handdiagram edge there is visible an inner frame 28 a that is pivoted in astraight line and dips a vehicle chassis into a treatment bath.

As shown by the carriage 20 c, the carriage is downwardly tilted away inthe region of the transfer station 18, and in doing so releases thevehicle chassis 22 c held by the carriage. At the same time, the vehiclechassis is transported away via a second conveying means.

The process of pivoting the carriages is shown even more clearly inFIGS. 9 and 10.

FIG. 7 shows the movement of the carriages, with the vehicle chassisheld by the carriages, into and through a tank 14. The carriages 20undergo translatory movement in direction of movement A and the innerframe moves relative to the outer frame via the lever assembliesexplained in FIG. 3 and which interact with a guide rail. In the exampleillustrated in FIG. 7, the vehicle chassis are immersed into the tank 14upside down, i.e. with the engine hood first, and are transportedthrough the tank in an upside down position. The advantage oftransporting the vehicle chassis upside down through the tank 14 is thatno sedimentation is produced on visible surfaces and, moreover, anycavities are readily flooded.

FIG. 8 shows schematically the sequence of different handling stationsof the system having carriages 20 according to the embodiment in FIGS.2, 3, 6 and 7. The individual vehicle chassis 22 are each held on acarriage 20, with the rotational movement occurring in the region of thetank 14 as a result of the lever assembly 38 and of the interaction witha guide rail 48 with inclined guide portions 48 a. Furthermore, thetransfer station 18 is shown, which has a pivoting means to downwardlypivot the carriages 20 through 90° in direction B, as depicted by thecarriage 20 d on the left side of the plane of projection. In the regionof the transfer station 18 when the carriage 20 is pivoted down, it isof course necessary to ensure that the handled vehicle chassis 22 c isreceived by a conveying means 26 depicted schematically in FIG. 8. Theconveying means can be designed such as to be located between theindividual arms of the inner frame and when the carriage is pivoteddown, the vehicle chassis is set down, as it were, on the conveyingmeans 48 and transported out of the system in the direction of arrow C.

In the embodiment shown in FIG. 8, the individual carriages do not havetheir own rotary drive or travel drive, with the result that they arepulled through the entire system by means of a pull technique. Theindividual carriages 20 are provided with coupling projections, witheach carriage 20 having a coupling projection 50 a and a couplingprojection 50 b on the opposite side. The individual carriages areguided through the system such that the correspondingly shaped couplingprojections 50 a and 50 b interlock with one another and therefore theindividual carriages 20 can be pulled, just like in a train, by thatcarriage 20 c which is respectively nearest to the transfer means 19before the carriage there, as a result of the pivoting movement B,downwardly disengages positively from the carriage 20 b disposedtherebehind in the direction of movement. The coupling means may alsohave the hook shape shown in FIG. 3. After the carriage in the transferstation 18 has pivoted, it is gripped by conveyor belts and returned inthe direction of movement D. One carriage during return travel isdesignated as 20 e in FIG. 8.

If a carriage in the transfer station 18 has been downwardly tilted, thecarriage 20 b which is now nearest to the transfer station 18 and theremaining carriages coupled to this carriage must, with the aid of adrive 52 or another pulling means, be conveyed to the transfer station18 in direction C of the translatory movement before the carriage 20 bis tilted downward in the next step, and the immediately followingcarriage, which is at this point in time located in the region of drive52, continues to convey, in the direction of arrow C, the remainingcarriages coupled thereto, again in the manner of a train. In the sameway, at the transfer station at the start of the handling line, a “new”carriage is again upwardly hooked, via the pivoting movement, into thechain of carriages located in the handling line.

That region, with the carriage 20 d, which is positioned in FIG. 8 inthe direction of movement in front of the transfer station 18 is amaintenance zone that enables operating personnel to have easy access tothe carriages for servicing and repair work.

FIG. 9 depicts the downward tilting of a carriage. The carriage 20 isguided by means of the lever assembly 38 on the guide rails 44 beneaththe aforementioned grating 24 that simultaneously serves as maintenanceaccess. A continuous partition element 66 is disposed on the side facingthe handling stations. In the transfer station 18, the entire carriage20, as already depicted in FIG. 8, is downwardly pivoted through approx.90° around a pivoting shaft 68, as indicated by the pivoting radii B.The pivoting shaft runs parallel to the translational direction C of thecarriages and is disposed on that side of the carriages which faces awayfrom the handling means, with the result that the downwardly tiltedcarriages cannot collide with the carriages in the region of thehandling line. During downward tilting, not just the carriage alone, butalso the guide rails in the region of the transfer station 18 arepivoted downwards, with the result that the carriage is accuratelyguided downwards during pivoting too. After pivoting downward, thecarriage is rapidly transported by the conveyor belt 70 to the furthertransfer station disposed at the start of the system and in which thereverse movement sequence B takes place and the carriage is pivotedupwards. FIG. 9 might therefore equally represent the transfer means atthe start of the handling line, because there is no difference betweenthe two transfer stations in terms of movement sequences, apart from thefact that a fixed connection with the vehicle chassis to be handled hasto be created in the first transfer means and has to be correspondinglyseparated again in the second transfer means.

FIG. 10 shows the same situation again, this time with a handlingstation 72 that effects spray treatment and as an alternative to theimmersion baths used so far in the detailed description of preferredembodiments, can, of course, likewise be disposed within the tunnel 12of the system. It is evident from the depiction according to FIG. 10that the best possible advantage is taken of the existing space as aresult of tilting the carriages down into the position designated as20e, because the carriages can, during return travel, be guidedalongside a possible tank 14 and the existing space is therefore takenadvantage of in the best possible manner.

FIG. 12 shows an alternative embodiment of the invention that uses acarriage 60. The depiction corresponds essentially to that in FIG. 8,though the provision of carriages 60 with their own travel drive andtheir own rotary drive makes a guide rail with inclined portions 48 aunnecessary. Furthermore, the carriages 60 are smaller in design and donot have any coupling projections 50 either. Finally, there is no needfor any drive for pulling a carriage disposed next to the transferstation 18. In agreement with the designation according to FIG. 8,reference number 60 c is used to designate that carriage which islocated in the region of the transfer station and reference number 60 bis used to designate that carriage which is located behind the carriage60 c in direction C of the translatory movement. The carriage 60 d islocated in a maintenance zone while the carriage 60 e is rapidlyreturned in the direction of arrow D. Due to the independent travel androtary drives, the travel direction can, moreover, be reversed region byregion, as indicated by arrow E. Any movement of the carriages cantherefore be performed within a handling region and particularly in theregion of a tank 14. The transfer to the transfer stations is effectedin the aforementioned manner that makes use of the carriages 20.

The transfer of information and power between the guide device as partof the first module and the carriages 60 is preferably effected via aninductive current transfer 80, as is evident from FIG. 14. It thereforebecomes apparent that the system according to the embodiment in FIG. 8is extremely easy to refit as the system according to FIG. 12 in thatchiefly various travel drives are used and the aforementioned additionaladaptation measures are taken.

In the same way, of course, one of the hybrid solutions that weredescribed in detail above and in which the carriages have just a singledrive, is conceivable too, as shown by way of example in FIG. 4. In ahybrid solution, the roller conveyor 46 for conveying the vehiclechassis to be handled, the pivoting means for the carriages and therapid return in which conveyor belts are used, correspond to those inthe embodiments described above.

FIG. 13 once more shows a top view of a travel drive 60 that has both atravel drive 62 and a rotary drive 42 and an accompanying control means64. The inner frame 28 is no longer shown in the embodiment according toFIG. 13; the depiction ends with the rotary shaft 32.

The advantages of the system according to the invention consist in theinterchangeability of the system modules (first module and secondmodule) while retaining the basic system as a first module having thebasic components of tunnel, tanks and guidance mechanism with transferstations. The system requires little space, because no space is lostbeneath the system and the smaller dimensions, furthermore, lead tosavings in steel construction. Additionally, bearings and joints can bepositioned outside the immersion media and optimum shaft sealing isachieved as a result of accompanying seals. With little refitting work,the system can, in the form of the electronic version shown in FIG. 12,be equipped with individual control of the carriages, separate traveland rotary drives, and maximum flexibility of the movement of theindividual carriages. Alternatively, the embodiment according to FIG. 8can also be realized using carriages that are rigidly linked together,whereby maximum reliability and a very high throughput are attainable.In contrast to conventional solutions using carriages that are linkedtogether rotationally, the advantage of using fewer carriages is,however, also achieved by means of the rapid return travel. It is notnecessary to adjust chains either. Yet hybrid solutions between the twoaforementioned solutions, in which for example the carriages are linkedtogether and only the rotary motors are individually controlled, areconceivable, too. Such a hybrid solution may achieve a high throughoutwhile simultaneously retaining high degree of flexibility. Particularlythe solutions with a separate rotary drive have the advantage that thechassis can be easily pivoted up and down within the tank and can dripoff at a freely selectable angle above the tank. The solutions that usean additionally present independent travel drive have the furtheradvantage that the chassis can be transported to the immersion reservoirat a high speed while the processing time inside the immersion reservoiror in a different kind of handling means can be reduced while keeping anunvarying chassis dwell time throughout the handling line. The mainadvantage, however, lies in the high degree of flexibility of thedevice, which can be produced at lower cost as a result of commoncomponents for the various customized versions and, moreover, offersscope for future production modifications to or reconfigurations of thesystem. Additionally, the special-purpose return travel of the carriagesminimizes the space needed by the overall system.

1. A device for modular construction for handling workpieces (22), inparticular vehicle chassis (22), said device comprising a first modulehaving a handling line (12) with one or more handling regions (14) forthe surface treatment of said workpieces (22); a guide device (44) alongsaid handling line (12) and disposed only on one side of said handlingline (12); and a second module having one or more carriages (20; 40; 60)to which said workpieces (22) may be fixed and which may be moved alongsaid guide device (44); wherein said carriages (20; 40; 60) eachcomprise an outer frame (26); an inner frame (28) that revolves around arotary shaft (32) relative to said outer frame (26), whereby saidworkpieces (22) may be fixed to said inner frame (28); said rotary shaft(32) of each carriage disposed in an essentially horizontal andperpendicular manner In relation to the direction of movement (C) ofsaid carriages (20; 40; 60) along said handling line (12), and at leastone (60) of said carriages (20; 40; 60) having both rotary and traveldrives (42, 64).
 2. A device according to claim 1, wherein said guidedevice comprises at least one rail (44).
 3. A device according to claim2, wherein said carriages (20; 40; 60) have rollers (30) that roll onsaid at least one rail (44) of said guide device.
 4. A device accordingto claim 1, wherein said first module further comprises a first transferstation (18) that interacts with a first conveying means for supplyingsaid workpieces (22) to be handled; and a second transfer station (18)that interacts with a second conveying means (46) for removing saidhandled workpieces (22).
 5. A device according to claim 4, wherein saidfirst module further comprises return means for conveying said carriagesfrom said second transfer station (18) to said first transfer station(18).
 6. A device according to claim 5, wherein said return means (70)has a switching means for transferring carriages into or out of amaintenance zone.
 7. A device according to claim 4, wherein saidcarriages (20; 40; 60) in said second transfer station (18) are pivotedthrough an angle of approx. 90° around a pivoting shaft (68) in theregion of said guide device (44), and said carriages in said firsttransfer station (18) are pivoted back through the same angle in theopposite direction.
 8. A device according to claim 7, wherein saidpivoting shaft (68) is disposed essentially parallel to said guidedevice (44) and on that side of said guide device (44) which faces awayfrom said one or more handling regions (14).
 9. A device according toclaim 1, wherein said carriages (20; 40; 60) and said guide device (44)are designed such that during the handling of said workpieces (22), allbearings are at any time disposed outside said one or more handlingregions (14).
 10. A device according to claim 1, further comprising arotary drive (42) on each carriage, said rotary drive being connected atthe output side in a rotationally rigid manner to said inner frame (28)of said carriages (40; 60).
 11. A device according to claim 10, whereinthe transfer of information and/or power from said first module to saidcarriages is effected contactlessly, particularly inductively.
 12. Adevice according to claim 1, further comprising a travel drive (64) oneach carriage for the translatory movement of said carriages (60) alongsaid handling line (12) said rotary drive (42) arranged for generatingrotational movement of said inner frame (28) relative to said outerframe (28); and the translatory movement being independent of therotational movement.
 13. A device according to claim 1, wherein saidcarriages (20; 40; 60) are structured and arranged to move along saidguide device (44) with each said carriage (20; 40; 60) supporting anindividual workpiece (22), and said second module is structured andarranged such that said one or more carriages (20; 40; 60) pivot aboutan axis (68) extending substantially parallel to a direction of movement(C) of the workpieces (22) along the handling line (12).
 14. A deviceaccording to claim 13, wherein said axis (68) is positioned to one sideof said handling line (12) and regions (14) extending substantiallyparallel to the direction of movement (C) of the workpieces (22) alongthe handling line (12).
 15. A device for modular construction forhandling workpieces (22), in particular vehicle chassis (22), saiddevice comprising a first module having a handling line (12) with one ormore handling regions (14) for the surface treatment of said workpieces(22); a guide device (44) along said handling line (12); and a secondmodule having one or more carriages (20; 40; 60) to which saidworkpieces (22) may be fixed and which may be moved along said guidedevice (44); wherein said first module is structured and arranged tocooperate and be combined with various types of said second module, saidfirst module further comprises a first transfer station (18) thatinteracts with a first conveying means for supplying said workpieces(22) to be handled; and a second transfer station (18) that interactswith a second conveying means (46) for removing said handled workpieces(22), said carriages (20; 40; 60) comprise an outer frame (26); and aninner frame (28) that revolves around a rotary shaft (32) relative tosaid outer frame, whereby said workpieces (22) may be fixed to saidinner frame (28); said rotary shaft (32) of each carriage is disposed inan essentially horizontal and perpendicular manner in relation to thedirection of movement of said carriages (20; 40; 60) along said handlingline (12), and further comprising means for lifting and/or incliningsaid rotary shaft (32) relative to said outer frame.
 16. A device formodular construction for handling workpieces (22), in particular vehiclechassis (22), said device comprising a first module having a handlingline (12) with one or more handling regions (14) for the surfacetreatment of said workpieces (22); a guide device (44) along saidhandling line (12); and a second module having one or more carriages(20; 40; 60) to which said workpieces (22) may be fixed and which may bemoved along said guide device (44); wherein said first module Isstructured and arranged to cooperate and be combined with various typesof said second module, said first module further comprises a firsttransfer station (18) that interacts with a first conveying means forsupplying said workpieces (22) to be handled; and a second transferstation (18) that interacts with a second conveying means (46) forremoving said handled workpieces (22), said first module furthercomprises return means for conveying said carriages from said secondtransfer station (18) to said first transfer station (18), and saidreturn means are in the form of a conveyor belt (70) or chain conveyor.17. A device for modular construction for handling workpieces (22), inparticular vehicle chassis (22), said device comprising a first modulehaving a handling line (12) with one or more handling regions (14) forthe surface treatment of said workpieces (22); a guide device (44) alongsaid handling line (12); and a second module having one or morecarriages (20; 40; 60) to which said workpieces (22) may be fixed andwhich may be moved along said guide device (44); wherein said carriages(20; 40; 60) are structured and arranged to move along said guide device(44) with each said carriage (20; 40; 60) supporting an individualworkpiece (22), said second module is structured and arranged such thatsaid one or more carriages (20; 40; 60) pivot about an axis (68)extending substantially parallel to a direction of movement (C) of theworkpieces (22) along the handling line (12), and said second module isstructured and arranged such that said carriages (20; 40; 60)additionally pivot about an axis (32) extending substantiallyhorizontally and perpendicularly to the direction of movement (C) of theworkpieces (22) along the handling line (12).
 18. A device according toclaim 17, wherein said second module is structured and arranged suchthat said one or more carriages (20; 40; 60) pivot approximately 90°about said axis (68) extending substantially parallel to the directionof movement (C) of the workpieces (22) along the handling line (12).